In article ,
Bill Turner wrote:
[...]
I'll say it again: Use the manufacturer's pulse rating specs. If they
don't provide such specs, you'd be better off finding one who does.

Also:

If the maker's specification says "2.5 times overload for 3 seconds",
don't figure that 3 times overload for 2.5 seconds is ok too.

Watch out for the voltage limits as well as power limits. With high value
resistors it is sometimes the voltage that limits you.

With SMT parts, all limits only apply if the part in mounted the way the
maker expected.

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